FIG. 7 is a side view showing a housing with a conventional type of an electronic parts holder incorporated therein. Herein it is assumed that an electronic parts holder 70 made of synthetic resin is previously mounted on a substrate 90.
The electronic parts holder 70 has a structure in which supporting arm sections 72, 73 are provided in erected posture on an upper surface of a basic body 71 of a holder, and claw sections 72a, 73a provided at tip sections of the supporting arm sections 72, 73 respectively are spaced at a specified distance. This claw sections 72a, 73a hold therebetween, as shown in FIG. 7, a basic body 81 of a light-emitting element 80 as an object for packaging making use of elasticity of the supporting arm sections 72, 73.
In the basic body 71 of the holder, an insertion hole 74 for passing therethrough each of a pair of terminals 83, 84 of a light-emitting element 80 which is electronic parts is provided at a position lower in the vertical direction from a central position thereof of each of said claw sections 72a, 73a.
The light-emitting element 80 has a flange section 82 under a basic body 81 of the element. This flange section 82 restricts upward movement of the light-emitting element 80 when held between the claw sections 72a, 73a.
Concretely, an opening section 91a for exposing the light-emitting element 80 therethrough is provided on a front cover 91, and the opening section 91a is adjusted at a position where the claw sections 72a, 73a contact the flange section 82 and at a height where a top surface of the light-emitting element 80 does not project from the opening section 91a.
However, in the electronic parts holder 70 based on the conventional technology, if an unnecessary clearance is generated between the flange section 82 of the light-emitting element 80 and the claw sections 72a, 72b, as shown in FIG. 7, a top surface of the light-emitting element 80 goes lower than an opening section 91a, so that an emission angle of a light beam emitted from the opening section 91a becomes narrower.
In this case, light emission lacks when the front cover 91 is viewed from the diagonal direction, which disadvantageously results in degradation of the light-emitting element. Especially, a smoke window is covered over the front cover 91, it is extremely difficult to confirm light emission from the light-emitting element 80.
It should be noted that, as an alternative structure for mounting the light-emitting element 80 on a substrate, there is a spacer structure (not shown herein) in which a spacer made of, for instance, rubber is attached to terminals 83, 84 of the light-emitting terminal 80. In the above-described structure in which the claw sections 72a, 73a are employed, projection of the basic body 81 of the element to the front cover 91 is prevented by a hooking structure between the flange section 82 and the claw sections 72a, 73a, but in this spacer structure, not only projection but also sinking of the basic body 81 of the element 81 can be prevented.
Generally, as in a case of the light-emitting element shown in FIG. 7, abank section 85 is generated at a joint section of each of the terminal 72a, 73a of the basic body 81 of the element. Because of this bank section, in a case where a dimensional tolerance of the bank section 85 amounts up to 1.5 mm, large influence appears in a height of the basic body 81 of the element when mounted in a housing, which in turn causes an incorporating error in the housing.
In other words, the basic body 81 of the element is raised upward by a space with the band section 85 according to the dimensional error of the bank section 85, so that the basic body 81 of the element presses the front cover, which sometimes generates a pattern error.
Especially to suppress loss in light emission from the light-emitting element 80, it is necessary to minimize a distance between a front cover and a top surface of a basic body 81 of the element, and also in relation to this requirement influence of non-uniformity in a dimensional tolerance of the band section 85 over quality of a housing is substantially large.